Two-and three-layer resist recording media and their use in forming patterned layers on a substrate are known. Such media generally are comprised of a base or planarizing layer and a patterning or photoresist layer. In a tri-layer recording medium, these layers are separated by an intermediate layer, generally an inorganic oxide or nitride, which functions as a hardmask. The intermediate layer may have functions other than as a hardmask, e.g. as an absorptive layer.
The incorporation of a dye into the base layer of a two-layer resist recording medium is disclosed, for example, in U.S. Pat. No. 4,362,809, issued Dec. 7, 1982. The incorporation of a dye into the base layer of a three-layer resist recording medium including a hardmask is disclosed in U.S. Pat. No. 4,370,405, issued Jan. 25, 1983. In each instance, the dye is present to prevent a loss of resolution by absorbing the light utilized to pattern irradiate the photoresist layer and thereby prevent light from reflecting from the substrate into nonirradiated portions of the photoresist layer.
A significant problem encountered heretofore in such recording media is that, where the absorptive layer containing the dye contacts the photoresist layer, the dye becomes dissolved in the solvent for the photoresist layer and is taken up therein. This occurs because both layers are frequently positive photoresist materials and, therefore, have the same or similar solvents. The dissolution of the dye by the photoresist layer causes the photoresist layer to become nonuniform and to have a highly variable response to the irradiating light. A solution to this problem has been found in accordance with this invention.